While team manager Brian O'Brien will definitely have his international swansong at Cardiff's Millennium Stadium, bowing out after five years at the helm, a couple of Ireland's veteran forwards may be foreseeing a similar scenario.
"It's a reasonable proposition to think this might be the last time we see this squad together. Age means some players are nearing the end of their Test careers," said O'Sullivan.
"After the Lions tour it will be time for less experienced players to make the transition into Test rugby, but we have to make sure the players we are bringing in are better than who we have at the moment."
Particularly in the front row, Ireland have had a consistency at the highest level which has been envied by the world's top sides.
The trio of Reggie Corrigan, Shane Byrne and John Hayes have started in all four of Ireland's Six Nations matches this year - a consistency only rivalled by Celtic cousins Scotland and Wales in the tournament.
34-year-old looshead Corrigan is the eldest - having made his debut against Canada in 1997 and lined out in 24 of Ireland's last 26 Tests.
Having made the Ireland bench in 1996, Leinster hooker Byrne (33) waited a full five years before making his international bow against Romania. Wales will be his 14th Test out of the last 15.
19 stone tighthead Hayes (31) - who equals his former Munster team mate Peter Clohessy's haul of 54 caps in Cardiff - has taken in 20 consecutive Tests since recovering from a groin injury in 2003. The Bruff bruiser scored his first international try for 2-and-a-half years against Scotland last month.
All three are still in with a shout of making the British and Irish Lions touring party - announced on April 11 - but the circumstances of age are certainly narrowing their options.
14 straight Test matches have followed for the 31-year-old Shannon legend -Ireland's longest serving current international - since the 2003 World Cup - and only England's Martin Corry - also 31 - has matched him in serving years as a direct opponent in this season's tournament.
Foley has faced the new wave of young international number 8s in the last five weeks - Italy's Sergio Parisse (21), Scotland's Allister Hogg (22) and Brive and France back row Julien Bonnaire (26).
Wales captain Michael Owen (24) lies in wait for Saturday.
O'Sullivan has promised Owen and co. "one hell of a battle" as the Dragons aim for their first Grand Slam since 1978, with Ireland still harbouring Triple Crown and Championship hopes.
"Wales have played the rugby of the championship - they've been outstanding right the way through, especially in attack where they have torn sides to shreds," added the Lions assistant coach.
"They are on a roll and confidence is very high. Wales have always had fantastic footballers. It's their national sport and at the moment they're playing like there's no tomorrow. We all had it in the back of our minds at the start of the Championship that Wales were the danger team.
"To win in Cardiff, in front of what is going to be a partisan Welsh crowd, is a massive challenge.
"But we believe we can win if we get things right. This Welsh team is going to take some beating but we will go there and given them one hell of a battle."